For Immediate Release

New Rochelle, NY, June, 30 2010 –The first major study of the effects of extreme altitude on human physiology was the highly successful Silver Hut Expedition of 1960-61. This landmark study / event yielded a wealth of valuable data and was a model for subsequent high-altitude investigations, several of which are celebrated in the current special issue of High Altitude Medicine & Biology, a peer-reviewed journal published by Mary Ann Liebert, Inc. (www.liebertpub.com). The entire issue is available free online at www.liebertpub.com/ham

“The Silver Hut Expedition was responsible for many firsts and…essentially all of the findings have subsequently been confirmed,” says John B. West, MD, PhD, Editor-in-Chief of High Altitude Medicine & Biology and Professor of Medicine and Physiology at the University of California, San Diego (UCSD), School of Medicine, in an editorial introducing the special issue. These extreme altitude projects were “responsible for a sea change in our understanding of severe hypoxia, but they also represent a monument to human endeavor under extremely difficult conditions.”

The Silver Hut Expedition, an ambitious, 9-month project led by Sir Edmund Hillary together with scientific leader Dr. Griffith Pugh, officially named the Himalayan Scientific and Mountaineering Expedition, compiled extensive physiological measurements to assess how humans used to living in the lowlands can acclimatize to extreme altitude over a prolonged period. “It was a very happy scientifically successful expedition,” says James S. Milledge, MD, a Silver Hut participant and author of the review, “The Silver Hut Expedition, 1960-61,” in this issue of the journal.

“American Medical Research Expedition to Everest,” by Dr. West, captures the daunting feat of obtaining the first human physiological measurements at the highest point on Earth, the peak of Mt. Everest. The results showed that extreme hyperventilation made it possible to reach altitudes above 8000 m without supplemental oxygen while maintaining a sufficient inspired oxygen pressure, supporting a hypothesis derived from high altitude modeling studies.

“Operation Everest II,” by Peter D. Wagner, MD, from the Department of Medicine at UCSD, describes a comprehensive investigation of the effects of extreme altitude on multiple organ systems, a study conducted in a high altitude simulator that mimicked the conditions the participants would experience on a 40-day ascent of Mt. Everest. The diversity and complexity of measurements obtained and the invasive nature of the studies performed could not have been obtained from real-life studies in the field.

In “Operation Everest III: COMEX ’97,” author Jean-Paul Richalet, from the Department of Physiology, University of Paris, France, recounts the simulated ascent of eight male volunteers over 31 days in a hypobaric chamber. Seventeen study protocols produced large amounts of information regarding the factors limiting physical and psychological performance and the physiological and pathological changes in various bodily functions.

Michael P.W. Grocott, from the Centre for Altitude Space and Extreme Environment Medicine, at University College London, and co-authors representing the Caudwell Xtreme Everest Research Group, describe the unique measurements of peak oxygen consumption, cerebral artery diameter and blood velocity, microcirculatory blood flow, and arterial blood gas obtained from 222 subjects that climbed to an altitude of at least 5300 m, to the Everest Base Camp, in 2007. In an astonishing accomplishment, arterial blood samples were obtained by puncturing the femoral arteries of four participants at an altitude of 8400 m.